Flexibilize automatic indention on help screens

The fixed width of 15 chars and using tabs for indenting route names and arguments on help commands cause problems for longer route or argument names. 

This fix is calculating the maximum length of all routes with the new method `calcMaxString()` and indents all routes with spaces instead of tabs. Works the same with the arguments on the help command for a route. Needed to add a `getRouteNames` method to `RouteCollection` as well. 

All tests still run through after implementing this.